Preheat oven to 350 degrees.
Start by creaming 1 cup of granulated sugar together with 6 tablespoon of softened butter.
Then add in 1 egg, 1 egg yolk and ½ teaspoon of vanilla and combine.
Next mix in ½ cup of buttermilk.
In a small bowl sift together ¾ cup + 2 tablespoon of all purpose flour, ¼ cup + 2 tablespoon of dark cocoa powder, ¾ teaspoon of baking powder, ⅛ teaspoon of baking soda, and ¼ teaspoon of salt.
Add the dry ingredients to the wet ingredients and combine.
Lastly mix in ¼ cup of hot coffee.
Line a cupcake pan with 14 cupcake liners and fill each cup ¾ of the way full. Bake the cupcakes at 350 degrees for 20-22 minutes, or until a toothpick/cake tester comes out clean from the centers.
Let the cupcakes cool in the pan for 5 minutes then transfer to a cooling rack to cool completely.